Okazawa, Noboru A perturbation theorem for linear contraction semigroups on reflexive Banach spaces. (English) Zbl 0259.47012 Proc. Japan Acad. 47, 947-949 (1971). MSC: 47A55 47D03 47B44 PDFBibTeX XMLCite \textit{N. Okazawa}, Proc. Japan Acad. 47, 947--949 (1971; Zbl 0259.47012) Full Text: DOI
Okazawa, N. Two perturbation theorems for contraction semigroups in a Hilbert space. (English) Zbl 0208.39103 Proc. Japan Acad. 45, 850-853 (1969). MSC: 47A55 47D03 47B44 PDFBibTeX XMLCite \textit{N. Okazawa}, Proc. Japan Acad. 45, 850--853 (1969; Zbl 0208.39103) Full Text: DOI